Temporal relationship between circannual levels of luteinizing hormone and testosterone in prepubertal boys with constitutional short stature.

In the present study we refer the results of our researches on LH and testosterone circannual variations in 72 prepubertal boys with constitutional short stature, aged 6 to 10 years. They observed the following life schedule: nocturnal rest from 2200 to 0600, meals at 0800, 1300, 1900. Plasma samples were taken at 0800 and LH and testosterone were measured by RIA. The single independent data were fitted a cosine function to evidence any rhythm and describe its parameters. A significant circannual rhythm in the LH (annual crest time in December) and testosterone (annual crest tine in July) levels was detected, with a phase difference between the two from about 160 degree to 180 degree, i.e. an antiphase. Our data suggest that a temporal relationship may occur between the circannual secretion of LH and testosterone in prepubertal boys.